xref: /linux/drivers/gpu/drm/omapdrm/dss/base.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP Display Subsystem Base
4  *
5  * Copyright (C) 2015-2017 Texas Instruments Incorporated - https://www.ti.com/
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/list.h>
10 #include <linux/module.h>
11 #include <linux/mutex.h>
12 #include <linux/of.h>
13 #include <linux/of_graph.h>
14 #include <linux/platform_device.h>
15 
16 #include "dss.h"
17 #include "omapdss.h"
18 
dispc_get_dispc(struct dss_device * dss)19 struct dispc_device *dispc_get_dispc(struct dss_device *dss)
20 {
21 	return dss->dispc;
22 }
23 
24 /* -----------------------------------------------------------------------------
25  * OMAP DSS Devices Handling
26  */
27 
28 static LIST_HEAD(omapdss_devices_list);
29 static DEFINE_MUTEX(omapdss_devices_lock);
30 
omapdss_device_register(struct omap_dss_device * dssdev)31 void omapdss_device_register(struct omap_dss_device *dssdev)
32 {
33 	mutex_lock(&omapdss_devices_lock);
34 	list_add_tail(&dssdev->list, &omapdss_devices_list);
35 	mutex_unlock(&omapdss_devices_lock);
36 }
37 
omapdss_device_unregister(struct omap_dss_device * dssdev)38 void omapdss_device_unregister(struct omap_dss_device *dssdev)
39 {
40 	mutex_lock(&omapdss_devices_lock);
41 	list_del(&dssdev->list);
42 	mutex_unlock(&omapdss_devices_lock);
43 }
44 
omapdss_device_is_registered(struct device_node * node)45 static bool omapdss_device_is_registered(struct device_node *node)
46 {
47 	struct omap_dss_device *dssdev;
48 	bool found = false;
49 
50 	mutex_lock(&omapdss_devices_lock);
51 
52 	list_for_each_entry(dssdev, &omapdss_devices_list, list) {
53 		if (dssdev->dev->of_node == node) {
54 			found = true;
55 			break;
56 		}
57 	}
58 
59 	mutex_unlock(&omapdss_devices_lock);
60 	return found;
61 }
62 
omapdss_device_get(struct omap_dss_device * dssdev)63 struct omap_dss_device *omapdss_device_get(struct omap_dss_device *dssdev)
64 {
65 	if (get_device(dssdev->dev) == NULL)
66 		return NULL;
67 
68 	return dssdev;
69 }
70 
omapdss_device_put(struct omap_dss_device * dssdev)71 void omapdss_device_put(struct omap_dss_device *dssdev)
72 {
73 	put_device(dssdev->dev);
74 }
75 
omapdss_find_device_by_node(struct device_node * node)76 struct omap_dss_device *omapdss_find_device_by_node(struct device_node *node)
77 {
78 	struct omap_dss_device *dssdev;
79 
80 	list_for_each_entry(dssdev, &omapdss_devices_list, list) {
81 		if (dssdev->dev->of_node == node)
82 			return omapdss_device_get(dssdev);
83 	}
84 
85 	return NULL;
86 }
87 
88 /*
89  * Search for the next output device starting at @from. Release the reference to
90  * the @from device, and acquire a reference to the returned device if found.
91  */
omapdss_device_next_output(struct omap_dss_device * from)92 struct omap_dss_device *omapdss_device_next_output(struct omap_dss_device *from)
93 {
94 	struct omap_dss_device *dssdev;
95 	struct list_head *list;
96 
97 	mutex_lock(&omapdss_devices_lock);
98 
99 	if (list_empty(&omapdss_devices_list)) {
100 		dssdev = NULL;
101 		goto done;
102 	}
103 
104 	/*
105 	 * Start from the from entry if given or from omapdss_devices_list
106 	 * otherwise.
107 	 */
108 	list = from ? &from->list : &omapdss_devices_list;
109 
110 	list_for_each_entry(dssdev, list, list) {
111 		/*
112 		 * Stop if we reach the omapdss_devices_list, that's the end of
113 		 * the list.
114 		 */
115 		if (&dssdev->list == &omapdss_devices_list) {
116 			dssdev = NULL;
117 			goto done;
118 		}
119 
120 		if (dssdev->id && dssdev->bridge)
121 			goto done;
122 	}
123 
124 	dssdev = NULL;
125 
126 done:
127 	if (from)
128 		omapdss_device_put(from);
129 	if (dssdev)
130 		omapdss_device_get(dssdev);
131 
132 	mutex_unlock(&omapdss_devices_lock);
133 	return dssdev;
134 }
135 
omapdss_device_is_connected(struct omap_dss_device * dssdev)136 static bool omapdss_device_is_connected(struct omap_dss_device *dssdev)
137 {
138 	return dssdev->dss;
139 }
140 
omapdss_device_connect(struct dss_device * dss,struct omap_dss_device * dst)141 int omapdss_device_connect(struct dss_device *dss,
142 			   struct omap_dss_device *dst)
143 {
144 	dev_dbg(&dss->pdev->dev, "connect(%s)\n",
145 		dst ? dev_name(dst->dev) : "NULL");
146 
147 	if (!dst)
148 		return -EINVAL;
149 
150 	if (omapdss_device_is_connected(dst))
151 		return -EBUSY;
152 
153 	dst->dss = dss;
154 
155 	return 0;
156 }
157 
omapdss_device_disconnect(struct dss_device * dss,struct omap_dss_device * dst)158 void omapdss_device_disconnect(struct dss_device *dss,
159 			       struct omap_dss_device *dst)
160 {
161 	dev_dbg(&dss->pdev->dev, "disconnect(%s)\n",
162 		dst ? dev_name(dst->dev) : "NULL");
163 
164 	if (WARN_ON(!dst))
165 		return;
166 
167 	if (!dst->id && !omapdss_device_is_connected(dst)) {
168 		WARN_ON(1);
169 		return;
170 	}
171 
172 	dst->dss = NULL;
173 }
174 
175 /* -----------------------------------------------------------------------------
176  * Components Handling
177  */
178 
179 static struct list_head omapdss_comp_list;
180 
181 struct omapdss_comp_node {
182 	struct list_head list;
183 	struct device_node *node;
184 	bool dss_core_component;
185 	const char *compat;
186 };
187 
omapdss_list_contains(const struct device_node * node)188 static bool omapdss_list_contains(const struct device_node *node)
189 {
190 	struct omapdss_comp_node *comp;
191 
192 	list_for_each_entry(comp, &omapdss_comp_list, list) {
193 		if (comp->node == node)
194 			return true;
195 	}
196 
197 	return false;
198 }
199 
omapdss_walk_device(struct device * dev,struct device_node * node,bool dss_core)200 static void omapdss_walk_device(struct device *dev, struct device_node *node,
201 				bool dss_core)
202 {
203 	struct omapdss_comp_node *comp;
204 	struct device_node *n;
205 	const char *compat;
206 	int ret;
207 
208 	ret = of_property_read_string(node, "compatible", &compat);
209 	if (ret < 0)
210 		return;
211 
212 	comp = devm_kzalloc(dev, sizeof(*comp), GFP_KERNEL);
213 	if (comp) {
214 		comp->node = node;
215 		comp->dss_core_component = dss_core;
216 		comp->compat = compat;
217 		list_add(&comp->list, &omapdss_comp_list);
218 	}
219 
220 	/*
221 	 * of_graph_get_remote_port_parent() prints an error if there is no
222 	 * port/ports node. To avoid that, check first that there's the node.
223 	 */
224 	n = of_get_child_by_name(node, "ports");
225 	if (!n)
226 		n = of_get_child_by_name(node, "port");
227 	if (!n)
228 		return;
229 
230 	of_node_put(n);
231 
232 	for_each_endpoint_of_node(node, n) {
233 		struct device_node *pn = of_graph_get_remote_port_parent(n);
234 
235 		if (!pn)
236 			continue;
237 
238 		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
239 			of_node_put(pn);
240 			continue;
241 		}
242 
243 		omapdss_walk_device(dev, pn, false);
244 	}
245 }
246 
omapdss_gather_components(struct device * dev)247 void omapdss_gather_components(struct device *dev)
248 {
249 	struct device_node *child;
250 
251 	INIT_LIST_HEAD(&omapdss_comp_list);
252 
253 	omapdss_walk_device(dev, dev->of_node, true);
254 
255 	for_each_available_child_of_node(dev->of_node, child)
256 		omapdss_walk_device(dev, child, true);
257 }
258 
omapdss_component_is_loaded(struct omapdss_comp_node * comp)259 static bool omapdss_component_is_loaded(struct omapdss_comp_node *comp)
260 {
261 	if (comp->dss_core_component)
262 		return true;
263 	if (!strstarts(comp->compat, "omapdss,"))
264 		return true;
265 	if (omapdss_device_is_registered(comp->node))
266 		return true;
267 
268 	return false;
269 }
270 
omapdss_stack_is_ready(void)271 bool omapdss_stack_is_ready(void)
272 {
273 	struct omapdss_comp_node *comp;
274 
275 	list_for_each_entry(comp, &omapdss_comp_list, list) {
276 		if (!omapdss_component_is_loaded(comp))
277 			return false;
278 	}
279 
280 	return true;
281 }
282